Service observation arrangement for telephone systems



Amd-13,1926. y 1,580,398 Y w A. BENSON SERVICE OBSERVATION ARRANGEMENTFOR TELEPHONE SYSTEMS I1-mam :1P-

lnllham H Eansun Y w. A. BENSON l 'SERVICE OBSERVATION ARRANGEMENT FORTELEPHONE SYSTEMS April 13,1926. l 1,580,398 Y Filed t. 18, 1921 2Sheets-Sheet 2 l l l m l l Il Il )I L &

lnllham E Bsnsnn of the ringing current passes through the bridgedrelays 3l and 33, but only relay 31, which is tuned to respond to thisparticular frequency of ringing current responds. Relay 3l, uponenergizing, closes a circuit for' relay 32 at armature 48. Relay 32,upon energizing, locks itself up at armature 50 to conductor 87, whichis grounded through the resting contact of armature 57 and said armaturecloses a circuit for relay 37 at armature 47 and closes a circuit forthe lamp L at armature 49. The operator is apprised by the lighting ofthe lamp L of the fact that the subscriber at substation A is beingsignalled. Relay 37, upon energizing, prepares a locking circuit foritself at armature 97; closes a circuit for cut off relay 30 at armature96; and at armature 95 places a shunt around armature 55 and its restingcontact for a purpose to be explained more fully hereinafter.

' energizing', removes the tuned relays 3l and 33 from in bridge of theline at armatures 44 and 46 'so that they will not interfere with theringing of the bell at the called substation. lt will be noted that theringing curi rentl passes through the relays and 39 at this time. Relay39 does not respond owing` to its marginal adjustment and to the smallnumber of turns in its lower winding. rlhe armature of relay 35 is notappreciably affected by the current which passes through the said relayowing to the fact that the noninductive resistance 58 is shunted aroundthe relay at this time.

`When the subscriber at substation A responds to the ringing of his bellby removing his receiver, a direct current bridge is closed across'theconductors 2 and 3, whereupon the source of ringing current is removedby the .f lconnector switch and a source of talking current is connectedup instead.

The low i wound series relay 35 at the observing operators positionwhich did not respond to the ringing current Von account of the noninductive shunt around it now responds to the direct talking current byoperating its armas ture 54, thereby closing a circuit for release relay36. Relay 39 however, being marginally adjusted does not respond at thistime owing to the fact that its armature cannot i be attracted untilcurrent flows through both ground upon conductor 86. Relay 32, upondeenergizing, opens another point in its circuit at armature 50; opensthe circuit of the lamp L at armature 49; and at armature 47 opens theinitial energizing circuit of relay Cut off relay 30, upon- 37 andcloses the followinglocking circuit for the said relay 37: from groundby way of conductor 86, working contact of armature 97 of relay 37 andsaid armature, normally closed contacts controlled by armature 47,normally closed contacts cont-rolled by armature 73, and relay 37to-'battery. Vhen ground is placed upon conductor 86 a circuit is closedfor the upper winding of electro polarized relay 39. vRelay 39, how--ever, is not energized at this time owing` to the fact that the currentflowing in either winding opposes that flowing in the other. A branch ofthis circuit extends also by way of armature 62 and its resting contactto the lamp L2 which becomes lighted to notify the observing operatorthat the called subscriber has answered. Another branch of this circuitextends from conductor 86 by way of armature 59 of relay 38 and itsresting` contact and armature 69 and its resting contact to battery, byway of magnet 90 of the recorder R. Magnet 90, upon energizing, attractsits armature 91, thereby forcing the pencil 93 intoV engagement with themoving tape 92. This tape it may be said is suitably marked and dated sothat a record as to what time and upon what day a call was made orreceived can be had. A mark is made on the tape the length of whichdepends upon vthe length of time during which the magnet 90 isenergized. i

The called subscriber, of course, may begin to converse with the callingsubscriber as soon as he removes his receiver and is not aware of any ofthe events which are taking place at the recording operators position.As much as is shown of the talking circuitv is outlined by heavyconductors and it will be observed that it includes the lower winding ofrelay 39. The lower winding of relay 39, however, has comparativelylittle inipedence and consequently does not appreciably interfere withthe transmission of voice currents.

l/Vhen the conversation is completed the calling and called subscribersreplace their receivers. When the receiver is replaced at the substationA the circuit of relay 35 is opened and the said relay, upond-eenergizing, opens the circuit of relay 36 whereupon relay 38energizes in series with relay 36 and opens the circuit of the magnet 90of the register R at armature 59. Magnet 90, upon deenergizing, removesthe pencil 93 from engagement with the tape 92 thus terminating the markbeing made on the latter. As

a further result of the energization of relay 38 it places the operatingmagnet 75 of the switch D in multiple with release relay 36 at armature58, the circuit including arma.- ture 64 and its resting contact. Owingto the high resistance of relay 38, operating magnet 75 does notenergize and release relay 36 deen'ergizes. Upon deenergizing, re-

lease relay L 36 .op'ensithe circuitof relayv 38 Aat .armature 56 andremoves ground from conductor 86 vat ,armaturev 57. Relays 37 Theopera-tor uponv noting-that the lamp L2has becomefextinguished knowsthat the conversation has terminated and vthat the called subscriberlhas replaced his receiver. She'may Amake vouta ticket if' desired or inany suitable way'record the information thatv' 1 resting contact for themagnet y90 of the l she has gathered. Y y

In regard to the -line Vswitch C it maybe said that switching relay 1ldeenergizesupon the -release of the connector switch which was :used to`completer the connection, yand upon so doing restore-s the conditions inthe lineV switch Cto normal'.` 1 f ltwill be assumed now thatvthesubscriber at substation A desires to Ycall so-me other subscriber.VWhen the vreceii'fer is removed at substation A, a Vcircuit 'is closed.over the lin-e conductors 2 and3, conductors 2V and 1 tors 4 and 5,-forline relay l2 of the line switch'C. Linel relay l2,^upon energizing,

places ground .upon private normal. con-. duct-or 6 at armature,v 18,thereby closinga' circuit for switching'relay l1 and stepping n an idletrunk line leadingto a iirst selector and when one is found theswitching relay 11 Y energizes, not rhaving energized lbefore.

on accountof being short circuited bythe ground potential `whichis-kencountered test wiperQl in passing 4over busy testv contacts.Switching. relay 1l, upon energizing,

disconnects the line conductors 4 and 5 from i the winding of linerelayl v12 and ground re-v spectively andext'en'ds them by way ofarmaturesv13 and l5 and wipers20 and tothe line relay fof `theirstselector to whichv the t-runk line upon which the, wipers ai'e ermtending atv this time. The line "and release relays of the said selectornow energize in v the well vkno-wn manner andthe latter places groundupon the associated .release trunk conductor, thereby 'closing a4holding circuit for the switching relayll in the usual inanner. i l Y 1Inl 'the equipment torsposition, 4'relay'39does not energize forvreasons hereinbeiore given but relay 35,1up-

' on energizing, closes acircuitffor relay '36 at armature 54. Relayv36, upon energizing, re-

moves? the resistance l58 fromin shunt ofV relay 35 atarmature 55;prepares a circuit forfrelay 38 -at` armature Y56;-.disconnectsYgroundfromconductor 87 and places ground upon conductor 86 at armature57. ,Ingre- The line switch C now operates'in tliewell known manner toselect n atthe recording opera' spense to tlieplacing of grounduponfcon` yductor 86y the lamp L2` becomes lighted to apprise'theoperator of the fact that a subscriber has his receiver oli' the hook."A cirregister R, withthe` result that armature 91 is attractedand thepencil 93 begins to make a mark upon the moving tape. 92. As' a' furtherresultl ot' placing ground lupon con-` ductor 86a circuitisclosed orcutyoft' relayY 30 including the resting., contact of armature 96 and saidarinature.fCut oii' relay 30, upon energizing, disconnects the" tunedrelays- 3l and 33 at armatures 44 and 46. Y,

The vcalling subscriber ,mayl now operate his calling device inaccordance jwith the irst digitotthe desired number, thereby bo yproducing a correspondingnumberof interruptions in thecircuit of theline relay vof `the first selector to which the connection has beenextended. v lIn responseto these interruptions the saidliiie relaycauses the selector to raise its wipers to thedesire'd level andyrrotate them in search of an idle rtrunk line leading to a connectorswitch, assuming vof course, that this` is a 1000 linesystem. In theequipment at the observing operatc'rs ido position, relay 35 falls backeach time an ,-5

interruption isg'produced in its circuit and,

upon fallingV back in responsev to the first interruption, removesv ashort'circuit' from around relay 38.' Relay 38, upon energiz-VVV ing,i`n series withvrelease relay 36, removes ground from the upper set ofwipers of the switches D-D2, inclusive,` at armature 60;

v'opens the circuit or'thcinagnet 90 of the register R at armature 59;and at armature V'58 places the operating magnet 7 5 of the switch D inmultiple with release relay 36. Operating magnet .7 5, however, does noten# ergize at this timek on account of the high resistance ofrelay 38.Relay 35, upon energizing, following the interruption produced A Vin,its circuit, short circuits relay. 38 yand closes a circuitfor'lrelayv36 vand operating magnet v7 5 .in multiple at armature 54.

Magnet 7 5, uponl energizing, advances theA wipersof the switch D intoengagement with the first set of lbank vcontacts.`v Relay 38, beingshortcircuited, does'not fallback im'- mediately andl consequentlyretainsits armatures attracted throughout the series of interruptions.Then relay 35 deene'rgizes in response to the second interruptionsproduced in'its circuit magnetz'' deenergizes not being able to; retainVits arniature'attracted-V in series with the high resist-ance re"- liolay 33. (,lperating magnet 75 is energized again each time relaycnergizes and by its subsequent operation advances the wipers of theswitch D into engagement with the set of bank contacts corresponding tothe digit called. At the end of the series of interruptions relay cornesto rest in an energized condition, whereupon relay 33 deenergizes andopens the circuit of operating magnet 75 at armature 53; closes thecircuit of the magnet 90 of the register R at arn'iature 59 thusstarting another mark on the tape 92; and at armature 60 places groundupon the upper set of wipers of the switch DD2, inclusive, therebyclosing the following circuit for relay 420: From ground by way ofarmature 57 and its working contact, armature 60 and its restingcontact, upper wiper of the switch D, the bank contact upon which thesaid wiper is resting, normally closed contacts controlled by armatureG3, and relay -lfO to battery. Relay 40, upon energizing, closes alocking circuit for itselt and disconnects itself from the wiper ofswitch D at armature 33, and at armature 3l shifts the operating circuitfrom magnet 75 of the switch D to the magnet 76 'bf the switch D.

ln response to the calling of the second digit in the desired number thec'nnector switch to which the connection has been eX- tended raises itswipers step by step until they stand opposite the level of contacts inwhich the desired line terminates.

ln the equipment at the observing operators position the pencil 93 ofthe rea R is raised from the tape 32 during the calling of this digit inthe saine manner be* fore and the operating magnet 76 ot the switch Doperates in the same mannsr as the magnet of the switch D operatedduring the calling of the previous digit and steps the associated wipersaround to the set of bank contacts corresponding` to the digit called.At the end of this digit relay 33 falls back as before with the resultthat the pencil of the register R is brought into engagement with theassociated tape again; the circuit of operating magnet 76 is opened; andground is placed upon the upper set of wipers of the switches D, D andD2. rlhis ground potential entends by way of the upper wiper of theswitch D, the bank contact with which it is in engagement, normallyclosed contacts controlled by armature and relay ll to battery. Relaysi, upon energizing, locks itself to conductor 36 and disconnects itselffrom the wiper of the switch D at armature 65, and at armature 66tansfers the operating circuit to the operating magnet ZT of the switchD2.

Y ln response to the calling of the next and last digit in the desirednumber the connector switch to which the connection has been extendedrotates its wipers step by step until they come to rest` upon the bankcontacts in which the desired'line terminates. The connector switch nowAsends out ringing current intermittently to ring the bridged bell atthe called substation.

At the observing operators position the results produced by the callingof the'linal digit are similar to the results produced by calling theprevious digit and consequently the operating magnet 77 responds byrotating the wipers of the switch D2 into engagement with the set ofbank contacts corresponding to the digit called. At, the end of thisseries of interruptions relay 38, upon falling back7 in addition to theother operations performed, places ground upon the wipers of .theAswitches DD2, inclusive, thereby closing a circuit for relay l2including the upper wiper of the switch D2 and the normally closedcontacts controlled by armature 63. Relay 42, upon energizing, locksitself to conductor 86 and disconnects itself from the wiper of theswitch D2 at armature 68; shifts the operating circuit from magnet 7T ofthe switch DL to battery through the resist-ance 93 at armature 70;

opens the circuit of magnet 90 of the registe at armature 69; and atarmature 67 disconnects the lamp L3 from the working contact of armature62 and connects up the lamp lll instead.

lsllien the called subscriber answers, V the connector switch in a wellknown manner reverses the current flow in the incoming trunk conductorsand consequently'in the conductors leading back through the equip,"

ment at the observing operators position to the calling substation. Whenthis occurs he two windings of electropolarized relay 39 whichheretofore have opposed each other now assist each other in operatingthe said relay. Relay 39, upon energizing, replaces the resistance 58 inmultiple'with relay 35 at armature G1. rlhis is done so as to afford abetter path for the voice currents. As a further result of theenergization of relay 39 it disconnects the lamp L2 and connects up thelamp L4 at armature 62 whereupon the lamp L2 becomes extinguished andthe lamp L4 becomes lighted to inform the operator that the calledsubscriber has answered. rfhe calling and called subscribers may nowconverse with each other as desired, much of the talking circuits asvare shown being outlined by the heavy conductors.

The oberving operator not only knows that the calling subscriber hascalled a number and that his call has been answered but also knows whatnumber-helias called. This is made possible by the bank of lamps whichis suitably arranged before her so as to display the called number. Thisbank of lamps is connected one to each contact over which the lowerwipers of the switches D-D2, inclusive, pass, and consequently one lampv normal position.

from each switch is; lighted, as soon `as the;v

switch is operated, to show the positionr of.

the Wipersk of that switch, which in turn: is

indicative of the number called. Ofthese; lamps-only one for eachswitchy is shown, the others, Which arey connected in theY samel manfner as the one shown, bein-g omitted for the salieof simplicity. i

lNhen the conversation is iinisliedi'theacalling and called subscribersreplace their re,-

ceirers. 7Whenthe` receiver is-replace'd' at the substation A, thecircu-itefof thelineref( layer' the connector through which the-conf'neet-ien has been extended is op e1ied-,\vhereupon the` automaticswitches are'v restored toi lnormal in the usualV manner.` At theobserve ing operators Aposition relay 35 deenergizes in response te thereplacing of the receiver at the calling substation and opens the cir-.

cuit ci release relay 36 whereupon relayl 38. energizes inl series vviththe saidrel'ayfr and places resistance 93 in' multiple with releaserelay 36 at armature` 58. Resistance 93. is lower thantheiesistancefoflrelay 36 and'.y most of the current which comesthroughythe high Wound relay 38l flows through the saidresista-nce 93.v Asaresult release relay 36 ydeenergizcs and -upon so doingy opensthecircuit of relay 38 at armature 56, Whereuponrelay 3S deenergizes also.vAs afurther result of the deenergization of release relay' 36 itremoves ground from conductor 86 whereupon relays 40e-42, inclusive,vdeener'- gize and the. lamp L4 becomes extinguished.. As a furtherresult ofthev removal ot ground from conductor 86,. cut-"oil relay 30deenerA gizes and connects up thetunedfrelaysyl..

and 33 at larmatures 44 andati@` Asi aV still further resultv of thedeenergizationof; 're,

lease rela-y- 3.6,*it places ground; upon1 conductor 87 at armature57thereby closing a circuit for releasefinagnets-78, 79, vand 80 in,Vvmultiple 'through the, olii-normal contacts 8l., 82, and 83?. By theoperationigof these r e,- lease inagnctsftheWipers ofthe switches` D,D-, and D2 `are restored to normal `po sition, the circuit of each ofthe release mag nets being broken at its associated olf-normall contactswhen the associated Wipers rea-ch.I

now restored to normal position and' isr'eadyV for another call-eitherincoming or outgoing..A

`From an examination of the drawings it 'may be seen that when a.subscriber at substation A is'cal'led the operation ofthe equipment atthe observing operators po sition is the same as When thesubscrjiber atsubstation A. is called With the exception that the tuned ,relay 33responds in this case and closes ay circuitV 'for rthe associated relay34:. Relay 34,'upon energizing closes a locking circuit for itself,closes al circuit for relay S7, and closes acircuit'for the lamp L..Since the subscriber at' sub- The entire, apparatus is l is disclosedin station A has made no complaint regarding his service the operatorneed not payanyat-i tentionj tothe-lighting of the laInpLf.` 5

It sometimes happens ,that the conductorsioi? avg trunk, line becomeaccidentally reversed.; This may not caues anytrouble vtofariseiii somel'cases but' when lthe con` Y nectron is.extendedthroughV an automatic.

repeater ,the reversal yof' currentwhich` oc; curs when .a trunk: lineVist selected in vvhijch f the=conductors are, reversed causesI the; op?eration of certain Telaysinl the repeater which render .thef impulserepeating. circuit;

Vinoperative-.randi consequently prevents the connection vfreni*beingextended any further. lit the subscriber Whose line is underoblservation,is making a calli andrjone, o the l selecting;KV switchesin*l the exchange cue-ts through upon ka reversed trunkthe.--vel'peetio-v .polarized -relay ,39l atthe4 l,reclordin-g op.,-

erators lposition immediate]y energizes and extinguishes the kruip-L2.Since allof the-f digits of: the desired nu-nfiberv have not yet.beencalled relay i2 Willi.not be energizedV and thelanip Ljis lightedinstead of tlief. 1

lampvL* which lights upon.V the respons'elfof .The opera-tor, upon thecalled subscriber. noting the lighted condition ot thev lam-p L3,-throvvs the key K, which is a combined Pelea-Se; and holding. key, intoholdingposition, therebybridging the,l impedance coilf to holdup theconnection in casethecalling subscriberrcpl-aces-, his receiver.v I `Theop-l erator now observes the indicating .la-inps and determinesWhatroutetlie call ha-s ,taire-n;

`45 across the conductors 2 and. 3( iso asv ico and 'hovv many digitshavebeen. called... Thisinformationshe gives-to anl attendant H Whomakeshaste to itin-dythe/reversed triml Assoon ias, the attendant*hasvdisccfiveredv which- 'trunk isI in trou-blehe (mayl release` theswitch*through vvhiehv the cormectioigiv lis extended to it and makethee trunkbusy until helaas time to-*.clear upV the trouble. As soon asthe attendant hasrlocatedgthe trunk which ,is giving the.y trouble; henoti,

nec-tion is releasedzthe'operator restores the kkey K to normal andtells the calling subscriber that he may proceed again to' callthedesirednumber int theusual ina-linen.:

i In case the observing operator suspects thatfthe speedof thesubscribers calling-,I

device is too; high or too lou@ she may-.test

the speed yby operating tliefltey K which. connects a calling devicespeed indicator to: the operating lead. Sucha speedk indicator derail.in; the s.V raient switch C, Fig. 1.

1 vents a subscriber from setting up a des-ired connection lies in theline switch in which his line terminates. It the observing operatorsuspects that such is the case, she may operate the key K2, therebydisconnect'- ing the line switch C and connecting up another line switchto which the leads 71 and 72 associated with the key K2 are assumed toextend. This other line switch, of course, may be identical with theline If the operator observes that the calling subscriber always getshis number when this other line switch is connected up but not when theline switch C is connected up, shemay reasonably assume that the troublelies in the line switch C, and may make a report to an attendant whowill determine if her assumption is correct.

The various features of the invention having been described will now bepointed out in the appended claims.

What I claim is:

1. In an automatic telephone system, a plurality of subscribers lines,means including automatic numerical switches for setting up a connectionfrom a calling one of said lilies to a called one of said lines, meansfor placing a certain line under observation, and means operated onlyduring the setting up of a connection from the line under observationfor displaying the number of the called line. Y

2. In av telephone system, a calling subsc-ribers line terminating atone end in a subscribers instrument and at the other end in an automaticswitch, a plurality of other lines, means including said switch forsetting up a connection between the calling line and one of said otherlines, a` relay inserted in said calling line between the subscribersinstrument and said automatic switch, and means controlled by said relayfor displaying the number of the line with which the A calling line isconnected.

3. In a telephone system, a plurality of subscribers lines, meansincluding subscriber controlled numerical automatic switches for settingup a connection from a calling to a called one of said lines responsiveto the calling of the digits in the numler of the called line, means forplacing a certain line under observation, a digit space time recorder,and means for operating said time recorder whenever' a connection isbeing set up from the line under observation to another line.

4. In a telephone system, a plurality of subscribers lines, meansincluding subscriber controlled numerical automatic switches for settingup a connection from a calling to a called one of .said lines responsiveto the calling of the digits in the number of the called line, means forplacing a cert-ain line under observation, a time recorder, means foroperating said time recorder rendered effective whenever a call isinitiated from the line under observation, and means for rendering saidlast named means inoperative during the calling of each digit in thenumber of the called line.

5. In a telephone system, a plurality of subscribers lines, meansincluding sub-- scriber controlled numerical automatic switches forset-ting up a connection from a calling to a called one of said linesresponsive to the calling of the digits in the number of the calledline, means or placing a certain line under observation, a digit spacetime recorder, means for operating said time recorder whenever aconnection is being set up :trom the line under observation to anotherline, and means tor rendering said last named means inoperative afterthe calling of the last digit in the number or the called line.

6. In a telephone system, a subscriber-s line terminating at theexchange in an automatic switch, means including said switch and otherswitches controlled by the subscriber on said line for extending aconnec- -tion to another line, and means for automatiline terminating atthe exchange in an auto- V mat-ic switch, means including said switchand other switches controlled by the subscriber on said line forextending a connection to another line, an operators position, and meanstor automatically advising the operator at said position as to'whichline in the exchange the said subscriber is connected with.

8. In a telephone system a subscriber-s line terminating at the exchangein an automatic switch, means including said switch and other switchescontrolled by the subscriber on said line for extending a connection toanother line, an operatorie position, and means for displaying the-called number to the operator as soon as the connection is completed.

9. In a telephone system, a subscribers line terminating at the exchangein an automatic switch, means including saidswitch and other switchescontrolled by the subscriber on said line for extendingv a connection toanother line, an operators position, and means for registering thedigits in the line terminating at the'exchange' in an auto-vV maticswitch, means including said switch and other switches controlled bytheV sub-v scriber on said kline for extending'a connection to anotherline, a relay responsive to .all the digitsk of the callednumber, andaplurality of digit registering'devices con; trolled by Asaid relay. v

11. In a` telephone system, a subscribers line terminating at theexchange in van automatic switch, means including said switch and otherswitchesA controlled by the subscriber on said line for extendingaconnec` tion to another line, a relay responsive tok all the digits ofthe called number, a plurality of digit yregistering devices controlled'by said relay and a plurality of groups .of digit displaylampscontrolledby said registering devices. y y

12. In a telephone system, a subscribers line terminating atthe exchangein an au tomatic switch, means including said switch and other switchesycontrolled the subscriber on said line for .extending a connection toanother line, a relay responsive to all the digits of the called'number,means controlled by said relay for registering'the different digits, andmeans for-transmitting the complete number to an operator.

13. In a telephone system, a subscribers line terminating at theexchange infan .automatic switch, means including said switch and otherswitches controlled bythe subscriber on said line for extending aconnec-` tion to another line, a relay responsive to all the digitso thecalled number, an opera-Y tors position, and means controlled by saidrelay for registering the complete number and for displaying the same`at said Vposi-` tion.

14. In a telephone system, a calling subscribers line, automaticswitchescoiitrolled by the calling subscriber in accordance with thedigits in a called number to extend a. connection to anotherline, andmeans at the exchange for making a record of the time intervals whichelapse between the calling ot successive digits. 1 n

15. In a telephone system, acalling subscribers line, automatic switchescontrolled by the calling subscriber in accordance with the digits inacalled number to extend a connection to another line, arecording deviceat the exchange forl registering the length of the time intervals whichelapse between the calling of successive digits, and means forautomatically starting said devicel when the call is initiated.

16. In a telephone system, a calling subscribers line, automaticswitches controlled by the calling subscriber in accordance with lay,.and circuit arrangements for', shunting said relay responsive'to thesaid linebeing the digits in a called number to extend a connection'toanother line, ajrecorder at the ex change `,comprising a movingl tapeand means for marking the saine, means for bringing Asaid markingmeans-in contact with the tape vwhen .the call-'is' initiated, and means`for separating said marking means fromthe tape during the callingot'each digit of the number. n

17. In a telephone system, a subscribers line terminating at theexchange in4 an automatic switch, means including said switch 1 andother switches controlled by the sub scriber on said line for extendinga connection toanother line, an impulse senderat. the station on saidline by means of which said switches are controlled,an op'eratorsposition, means forr notifying the operator when the call is initiated,animpulse speed indicator, and meanswhereby the operator can causesaidindicator to be operated siinultaneously with said switches. Y

18; In a` telephonev system, a subscribers line .terminatingr at theexchange in' an au ltoniatic switch, means including said switch 'andother switchesY controlled 'by the; sub@A scriber on said line -forextending a connec-V tion to another line, an impulse sender at the`station on saidline by means ofwhich said switches are controlled, an`operators posi tion, means for notifying the operator when the call isinitiated, and a speed indicator at the operators positionfor'indicating to the yoperator the rate at which impulsesfaretransmitted tosaid switches. 19; In ay telephone system, a subscribersline terminating in an automatic switch for use Vwhen said line iscalling, other switches` for connecting with the said line when'the sameis called, a-relay connected in series with the said line between thesubscribers station` and said first switch andoperated over the twosides of .the said linein series registering mechanismv controlledbysaid reconnected in a conversational circuitv either as a calling or acalled`lline, said relay not being shunted when said line is a callingline and the desired connection is in process of being established.

20. In a telephone system, a line extend! ing'from a manual switchboardto an automatic switch, means including said switch and other Switchesyfor extending connection to a called line, means for reversing thedirection ot current flowl inthe vsaid line when `the called lsubscriberanswers, an answering supervisory signal responsive to the reversal,another supervisory signal, and means for operating the other signal incase the vdirection of current flow in said line is reversed before thecalled line is conl nected with. Y

party line, an operators position and means for notifying the operatorwhen the line is calling or being` called, said means serving also, incase the line is being called, for notifying the operator which of thesevera parties on the line is wanted.

22. In an automatic telephone system, a subscribers line, subscribercontrolled automatic switches for extending a connection to anotherline, an operators position, and means at said position individual tosaid subscribers line tor notifying the operator when the call isinitiated, when the first directively controlled switch involved in theconnection is operated, when the con`- nection is completed, and whenthe called subscriber answers.

Q3. In an automatic telephone system, a subscribers line, subscribercontrolled automatic switches for extending a connection to anotherline, an operators position, and visual means for notifying the operatorwhen the call is initiated, when each directively controlled switchinvolved in the connection is operated, and when the called subscriberanswers.

2li. In a telephone system, a subscribers line extending by way of amanual switchboard to an automatic switch," means including said switchand other switches con trolled by the subscriber on said line forextending connections to cailed lines, means for notifying the operatorwhen said iirst switch is out of order, another switch, and means atsaid switchboard whereby the opeator can substitute said last switch forsaid iirst switch to enable the subscriber to call. i

25. In a telephone system, a plurality of subscribers lines, meansincluding sub scriber controlled numerical automatic switches forsetting` up a connection from a calling to a called one ot' said linesresponsive to the calling of the digits in the number of the calledline, a time recorder, means for placing a certain line underobservation and for connecting said recorder therewith, and means foroperating said time recorder after the subscriber on the line underobservation has responded to a call. f

26. In a telephone system, a protector on the distributing :trame at theexchange, a subseribers line normally connected through said protectorand terminating in an automatic switch, a link circuit, and means forinserting` said circuit at said protector to include same in series withsaid line for observation or testing purposes.

27. In a telephone system, a protector on the distributing frame at theexchange, a subscriber-s line normally connected through said protectorand terminating in an automatic switch, observation equipment includingmeans for signaling an operator on calls incoming to and outgoing fromsaid line, and means for inserting said equipment at said protector toinclude saine in series with said line for observation purposes.

28. In a telephone system, a protector on the distributing frame at theexchange, a

subscribers line normallyconnected through said protector andterminating in an automatic switch, a test shoe, a link circuit havingboth ends terminating in said shoe, said shoe adapted to be insertedinto said protector to include said circuit in series'with said line,and means in said link circuit for enabling an operator to superviseincoming and outgoing calls to and from said line.

29. In a telephone system, a protector on the distributing frame at theexchange, a subscribers line normally connected through said protectorand terminating in an automatic switch, a test shoe, observationequipment connected to said shoe via a tour conductor cord, said shoeadapted to be inserted into said protector :for including said equipmentbetween the subscriber and said switch for Iobservation purposes.

In witness whereof, I hereunto subscribe my name this 10th day ofGctober, A. D., 1921.

WILLIAM A. BENSON.

